tests/test-run-tests.py

upgrade: move descriptions and selection logic in individual classes

Our goal here is to get top level definition for all the format variants. Having
them defined outside of the function enabled other users of that logic.

They are two keys components of a format variant:

1) the name and various descriptions of its effect,

2) the code that checks if the repo is using this variant and if the config
   enables it.

That second items make us pick a class-based approach, since different variants
requires different code (even if in practice, many can reuse the same logic).
Each variants define its own class that is then used like a singleton.  The
class-based approach also clarify the definitions part a bit since each are
simple assignment in an indented block.

The 'fromdefault' and 'fromconfig' are respectively replaced by a class
attribute and a method to be called at the one place where "fromconfig"
matters.

Overall, they are many viable approach for this, but this is the one I picked.

"""test line matching with some failing examples and some which warn

run-test.t only checks positive matches and can not see warnings
(both by design)
"""
from __future__ import absolute_import, print_function

import doctest
import os
import re
# this is hack to make sure no escape characters are inserted into the output
if 'TERM' in os.environ:
    del os.environ['TERM']
run_tests = __import__('run-tests')

def prn(ex):
    m = ex.args[0]
    if isinstance(m, str):
        print(m)
    else:
        print(m.decode('utf-8'))

def lm(expected, output):
    r"""check if output matches expected

    does it generally work?
        >>> lm(b'H*e (glob)\n', b'Here\n')
        True

    fail on bad test data
        >>> try: lm(b'a\n',b'a')
        ... except AssertionError as ex: print(ex)
        missing newline
        >>> try: lm(b'single backslash\n', b'single \backslash\n')
        ... except AssertionError as ex: prn(ex)
        single backslash or unknown char
    """
    assert (expected.endswith(b'\n')
            and output.endswith(b'\n')), 'missing newline'
    assert not re.search(br'[^ \w\\/\r\n()*?]', expected + output), \
           b'single backslash or unknown char'
    match = run_tests.TTest.linematch(expected, output)
    if isinstance(match, str):
        return 'special: ' + match
    elif isinstance(match, bytes):
        return 'special: ' + match.decode('utf-8')
    else:
        return bool(match) # do not return match object

def wintests():
    r"""test matching like running on windows

    enable windows matching on any os
        >>> _osaltsep = os.altsep
        >>> os.altsep = True

    valid match on windows
        >>> lm(b'g/a*/d (glob)\n', b'g\\abc/d\n')
        True

    direct matching, glob unnecessary
        >>> lm(b'g/b (glob)\n', b'g/b\n')
        'special: -glob'

    missing glob
        >>> lm(b'/g/c/d/fg\n', b'\\g\\c\\d/fg\n')
        'special: +glob'

    restore os.altsep
        >>> os.altsep = _osaltsep
    """
    pass

def otherostests():
    r"""test matching like running on non-windows os

    disable windows matching on any os
        >>> _osaltsep = os.altsep
        >>> os.altsep = False

    backslash does not match slash
        >>> lm(b'h/a* (glob)\n', b'h\\ab\n')
        False

    direct matching glob can not be recognized
        >>> lm(b'h/b (glob)\n', b'h/b\n')
        True

    missing glob can not not be recognized
        >>> lm(b'/h/c/df/g/\n', b'\\h/c\\df/g\\\n')
        False

    restore os.altsep
        >>> os.altsep = _osaltsep
    """
    pass

if __name__ == '__main__':
    doctest.testmod()